feat(config): remove polling usage
feat(config): remove polling usage

- Remove polling usage for file change watching with chokidar on Mac OS

Closes #2669

karma-runner/karma,maksimr/karma,david-garcia-nete/karma,johnjbarton/karma,karma-runner/karma,maksimr/karma,karma-runner/karma,karma-runner/karma,johnjbarton/karma,johnjbarton/karma,maksimr/karma,david-garcia-nete/karma,johnjbarton/karma,david-garcia-nete/karma